A modular sub-assembly solid rocket engine test bench device and cold flow test method

Abstract

The present invention relates to a modular subassembly and assembly solid rocket engine test bench device and a cold flow experiment method. It includes an engine support frame, an engine main body and supporting test equipment. The engine support frame supports the engine main body, and the supporting test equipment acquires data; the engine main body includes a tracer particle mixing section, a round-to-square transition section, a steady flow section, a flow regulating section, a front combustion chamber, a gas mixing section, an afterburner and a tail nozzle connected in sequence by flanges; the axial air inlet and the lateral air inlet are respectively arranged on the tracer particle mixing section and the gas mixing section, and are connected to the air supply system; the front combustion chamber, the gas mixing section and the afterburner are all equipped with observation windows; the steady flow section, the front combustion chamber, the gas mixing section and the afterburner are all equipped with pressure and temperature sensors to acquire the pressure and temperature data of the trajectory in the engine main body. The modular subassembly and assembly of the present invention is simple to operate, and sensors at multiple locations obtain real-time pressure and temperature data of the flow field in the engine during the entire experiment.

Description

Technical Field

[0001] The invention belongs to the technical field of rocket engine testing, and in particular relates to a modular sub-assembly and assembly solid rocket engine test bench device and a cold flow experiment method. Background Art

[0002] Strategic missiles are the core force of long-range strikes and strategic deterrence in countries around the world. In order to meet the challenges of upgrading advanced ballistic missile defense systems and continuously improving global rapid strike capabilities, strategic missiles must have the characteristics of "long-range delivery, high-mobility penetration", flexible deployment, diverse uses, and improved terminal penetration and survivability. Generally speaking, strategic missiles use solid rocket engines, which are easy to store and launch, so the engines are required to have high energy and performance control. The assembled solid rocket engine is one of the important technical approaches to achieve the high energy of the engine and propellant and the active performance control.

[0003] Compared with the traditional solid rocket engine system, the assembled solid rocket engine has two or more independent propellant combustion chambers, mixing combustion chambers and flow regulating devices, which increases the complexity of the system structure. It is necessary to consider the working process modeling elements of multi-factor coupling characteristics such as the self-sustaining combustion of rich fuel and oxygen-rich gas, the coupled combustion of the two gases, the mixing combustion chamber configuration and the oxygen-fuel ratio, and on this basis, obtain the actuation laws of the factors affecting the engine performance.

[0004] Compared with traditional cold flow experimental equipment, the modular assembled solid rocket engine test bench can consider the engine working state under the influence of multiple factors, and conduct separate studies on various influencing factors through the control variable method. At the same time, cold flow experiments can provide the regular characteristics of gas mixing and better grasp the efficiency of the mixed combustion of the two gases. Summary of the invention

[0005] The object of the present invention is to provide a modular sub-assembly and combination solid rocket engine test bench device and a cold flow test method.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A modular sub-assembly and assembly solid rocket engine test bench device, comprising an engine support frame, an engine body and supporting test equipment, wherein the engine support frame supports the engine body and the supporting test equipment acquires experimental data;

[0008] The support frame includes a first support block, a second support block, a reinforcing rib, an axial safety limit device and a base, the first support block and the second support block are fixed on the base, the reinforcing rib is connected to the axial safety limit device, and then fixed together on the base;

[0009] The engine body comprises a tracer particle mixing section, a round-to-square transition section, a steady flow section, a flow regulating section, a front combustion chamber, a gas mixing section, an afterburner and a tail nozzle which are connected in sequence through flanges; an axial air inlet is arranged at the front end of the tracer particle mixing section, which is connected to the air supply system; lateral air inlets are arranged at the top and bottom of the gas mixing section, which are connected to the air supply system; the side cover plate is connected by bolts to fix the observation window on the front combustion chamber, and the gas mixing section and the afterburner are both installed with the observation window and the side cover plate in the same way; a top cover plate is installed on the gas mixing section;

[0010] The supporting test equipment includes a pressure sensor base and a temperature sensor base; the steady flow section, front combustion chamber, gas mixing section and afterburner are all connected to the pressure sensor base and the temperature sensor base, and the pressure sensor and the temperature sensor are fixed to obtain the pressure and temperature data of the trajectory inside the engine body.

[0011] Furthermore, a porous medium plate and a probe are arranged inside the gas mixing section. The porous medium plate is embedded in a groove in the gas mixing section. The upper cover plate is connected by bolts, and a square hole is arranged in the middle of the cover plate. The top of the probe is connected to the sensor of the gas mixing section.

[0012] Furthermore, the flow regulating section adopts a gradual contraction-sudden expansion form, so that the upstream subsonic high-pressure gas is accelerated through the flow regulating section, and the pressure and temperature are reduced.

[0013] Furthermore, the circular-to-square transition section and the steady flow section both adopt a head-to-tail flange structure, and the flange is connected to the circular-to-square transition section (8) and the steady flow section by welding.

[0014] A modular sub-assembly combined solid rocket engine test bench cold flow test method, the specific steps are as follows:

[0015] 1. Connect the axial air inlet pipe and the lateral air inlet pipe to the axial air inlet hole and the lateral air inlet hole respectively by threaded connection;

[0016] 2. Build the Schlieren system in a "Z"-shaped optical path;

[0017] 3. Start the test by first turning on the high-speed camera, pressure sensor and temperature sensor to record the flow field inside the engine without gas;

[0018] 4. Open the valve of the air supply system and inject high-pressure nitrogen and argon into the engine. The gas flows into the particle mixing section and the steady flow section through the axial air inlet hole, enters the engine, and accelerates into the front combustion chamber through the flow regulating section. The gas flows into the top and bottom of the fuel gas mixing section through the lateral air inlet hole, flows steadily into the flow field inside the engine through the porous medium plate, meets and mixes with the axial incoming flow, and flows out of the engine through the afterburner and tail nozzle;

[0019] 5. After waiting for the pressure inside the engine to stabilize, close the air supply system valve, check the images recorded by the high-speed camera and the data collected by the sensor, and analyze the results.

[0020] The beneficial effects of the present invention are:

[0021] 1. The present invention is designed with an axial safety limit device to prevent the engine from axial displacement during the test run;

[0022] 2. All parts of the entire experimental device of the modular subassembly and assembly solid rocket engine test bench proposed by the present invention are modular devices, which greatly reduces the experimental cost;

[0023] 3. The modular sub-assembly and combination solid rocket engine test bench proposed in the present invention can adapt to different test models by replacing different sizes of flow regulating section radius, afterburner size, foreburner size and different gas mass flow rates, so as to compare the effects of different sizes of various engine devices on airflow mixing.

[0024] 4. The modular sub-assembly and combination solid rocket engine test bench proposed in the present invention can observe the mixing condition of gas in the fuel gas mixing section more carefully by using tracer particles combined with the schlieren method.

[0025] 5. The modular sub-assembly combined solid rocket engine test bench and cold flow experiment method proposed in the present invention have the characteristics of simple operation and easy disassembly, and can obtain real-time pressure and temperature data of the flow field in the engine during the entire experiment through sensors in multiple locations.

[0026] 6. The present invention proposes a modular subassembly combined solid rocket engine test bench and cold flow experimental method. The Schlieren method is used to observe the gas mixing phenomenon. The optical path arrangement of the Schlieren method adopts a Z-shaped optical path. The optical path is folded into a Z shape through two concave reflectors (Schlieren mirrors). The light source outlet and the knife edge are both arranged at the focus of the reflector. The advantage of the Z-shaped optical path is that the test section is in the parallel light. For the observation window of the gas mixing section, the light can pass perpendicular to the surface to avoid refraction, and the observation effect is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is the overall assembly diagram of the modular sub-assembly and combination solid rocket engine test bench device of the present invention;

[0028] Figure 2 It is an assembly diagram of the base, support structure and safety limit device of the modular sub-assembly combined solid rocket engine test bench device of the present invention;

[0029] Figure 3 It is an assembly diagram of the main structure of the engine of the modular sub-assembly combined solid rocket engine test bench device of the present invention;

[0030] Figure 4 It is an axial section view of the engine body of the modular sub-assembly and assembly solid rocket engine test bench device of the present invention;

[0031] Figure 5 It is an axial cross-sectional view of the flow regulating section of the modular sub-assembly and assembly solid rocket engine test bench device of the present invention. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with the accompanying drawings.

[0033] according to Figure 1 The engine model is obtained by scaling down a conventional solid rocket engine, and Q235 is selected as the material of the engine housing and the engine support frame, which has the characteristics of high strength and small mass. The main part of the present invention is composed of an engine support frame, an engine body and supporting test equipment. The engine support frame supports the engine body, and the experimental data is obtained through the supporting test equipment.

[0034] according to Figure 2 The axial safety limiter 4, the first support block 1, the second support block 2 and the reinforcing rib 3 of the engine support frame are fixed on the base 5 by welding. The first support block 1, the second support block 2, the reinforcing rib 3 and the base 5 are the main load-bearing structures. The support blocks are calibrated with a level gauge during installation. This structure can keep the engine in a horizontal state. The axial safety limiter 4 is divided into two parts, front and rear, and is fixed on the base 5 by welding. It can ensure that the engine does not undergo axial displacement during operation, limit the position of the engine, and ensure the safety of the experimental process.

[0035] according to Figure 3 The main body of the engine includes the following eight sections: tracer particle mixing section 7, round-to-square transition section 8, steady flow section 9, flow regulating section 10, front combustion chamber 11, gas mixing section 14, afterburner 19 and tail nozzle 20. Each section is connected by a flange 21 and sealed with a rubber ring. The axial air intake pipe and the lateral air intake pipe are connected to the axial air intake hole 6 and the lateral air intake hole 17 respectively by threaded connection. The air supply system delivers high-pressure and high-flow gas to the engine tracer particle mixing section 7 through the axial air intake pipe and the lateral air intake pipe, and then enters the steady flow section 9.

[0036] The tracer particle mixing section 7 adopts a round tube with a wall thickness of 10 mm. Tracer particles can be injected into the tracer particle mixing section 7 at the engine head, and a clearer image of the fuel gas mixing phenomenon can be obtained through the observation window 12.

[0037] The circular-to-square transition section 8 and the flow stabilizing section 9 both adopt a head-to-tail flange structure. The flange 21 is connected to the circular-to-square transition section 8 and the flow stabilizing section 9 by welding. Both provide a flow stabilizing effect. The axial airflow flows over a long distance and stably enters the flow regulating section.

[0038] The flow regulating section 10 adopts a gradually contracting-suddenly expanding form, which accelerates the upstream subsonic high-pressure gas through the flow regulating section, thereby reducing the pressure and temperature.

[0039] In the fore chamber 11, considering the existence of the propellant grain, the fuel gas will be hindered by the propellant grain during the flow in the fore chamber 11. Therefore, in order to simulate this flow phenomenon, a design scheme is adopted in which the inlet size of the fore chamber 11 is larger than the outlet size.

[0040] The observation window 12 and the side cover 13 are fixed to the front combustion chamber 11 by bolts, and a sealing groove is designed between the side cover 13 and the front combustion chamber 11, and a good air tightness is ensured by a sealing ring. The subsequent gas mixing section 14 and the afterburner 19 are fixed in the same way.

[0041] The top and bottom of the gas mixing section 14 are designed with lateral air inlet holes 17. The gas in the high-pressure gas cylinder is transported to the gas mixing section 14 through a pressure reducing valve and a hose. A porous medium plate 22 is designed in the gas mixing section 14. The high-speed airflow is more uniform after passing through the porous medium plate 22.

[0042] The porous medium plate 22 is embedded in the groove in the gas mixing section 14, and the upper cover plate is connected by bolts. A square hole is reserved in the middle of the cover plate to ensure smooth passage of gas while tightly fixing the porous medium plate 22 in the groove to avoid the dangerous situation of the porous medium plate 22 swinging during the experiment.

[0043] The temperature sensor base 18 and the pressure sensor base 16 are designed at the top of the steady flow section 9, the front combustion chamber 11, the gas mixing section 14 and the afterburner 19. The temperature sensor and the pressure sensor can be fixed thereto by threaded connection to obtain the temperature and pressure data of the flow field in the engine. The sensor of the gas mixing section 14 is connected to the probe 23 to more accurately measure the temperature and pressure of the internal flow field.

[0044] The tail nozzle 20 accelerates the expansion of the mixed gas, and the pressure and temperature are continuously reduced.

[0045] When the test begins, open the valve of the gas supply system, and the gas flows into the particle mixing section 7 and the steady flow section 9 through the axial air inlet 6, enters the engine, and accelerates into the front combustion chamber 11 through the flow regulating section 10. The gas flows into the top and bottom of the gas mixing section 14 through the lateral air inlet 17, and flows steadily into the flow field in the engine through the porous medium plate 22, meets and mixes with the axial incoming flow, and flows out of the engine through the afterburner 19 and the tail nozzle 20. The pressure sensor and the temperature sensor are fixed to the pressure sensor base 16 and the temperature sensor base 18 by threaded connection and measure the pressure and temperature of the flow field in each section. The sensor fixing and measuring methods in the steady flow section 9, the front combustion chamber 11 and the afterburner 19 are the same as above. The side cover plate 13 fixes the observation window 12 by bolt connection and rubber ring sealing. The observation window 12 with high light transmittance can observe the mixed gas mixing phenomenon more clearly.

[0046] according to Figure 4 A porous medium plate 22 and a probe 23 are designed in the gas mixing section 14. The porous medium plate 22 is made of a stainless steel sintered filter plate and is embedded in the inner layer of the gas mixing section 14 by means of a cover plate and bolt connection, so that the gas can evenly enter the internal flow field of the engine. The probe 23 uses a "five-hole probe" to accurately measure the temperature and pressure in the gas mixing section 14.

[0047] according to Figure 5 The cross-sectional configuration of the flow regulating section 10 is "gradually contracting-suddenly expanding", which plays a role in accelerating the flow of the gas. At the same time, the throat radius can be adjusted to control the mass flow of the gas to achieve the purpose of performance regulation.

[0048] Before the cold flow experiment begins, the device of the present invention builds the Schlieren system in a "Z"-shaped optical path to ensure good optical path quality so as to obtain a clear image of the mixed gas. At the beginning of the cold flow experiment, first turn on the high-speed camera and sensor to record the flow field in the engine without gas; then open the gas supply system valve, inject high-pressure nitrogen and argon into the engine, wait for the pressure in the engine to stabilize, close the gas supply pipeline valve, check the image recorded by the high-speed camera and the data collected by the sensor, and analyze the experimental results. When it is necessary to conduct experiments of different sizes of a certain module, after completing a set of experiments, only the changed module can be replaced and the experiment can be continued. This method can consider the influence of multiple factors on the mixing of the flow field in the engine.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A modular sub-assembly and assembly solid rocket engine test bench device, characterized in that: It includes an engine support frame, an engine body and supporting test equipment. The engine support frame supports the engine body, and the supporting test equipment obtains experimental data; The support frame comprises a first support block (1), a second support block (2), a reinforcing rib (3), an axial safety limit device (4) and a base (5); the first support block (1) and the second support block (2) are fixed on the base (5); the reinforcing rib (3) is connected to the axial safety limit device (4) and then fixed together on the base (5); The engine body comprises a tracer particle mixing section (7), a round-to-square transition section (8), a steady flow section (9), a flow regulating section (10), a front combustion chamber (11), a gas mixing section (14), an afterburner (19) and a tail nozzle (20) which are connected in sequence through a flange (21); an axial air inlet (6) is arranged at the front end of the tracer particle mixing section (7) and connected to the air supply system; lateral air inlet holes (17) are arranged at the top and bottom of the gas mixing section (14) and connected to the air supply system; the side cover plate (13) fixes the observation window (12) on the front combustion chamber (11) through bolt connection, and the gas mixing section (14) and the afterburner (19) are both installed with the observation window (12) and the side cover plate (13) in the same manner; and a top cover plate (15) is installed on the gas mixing section (14); The supporting test equipment comprises a pressure sensor base (16) and a temperature sensor base (18); the steady flow section (9), the front combustion chamber (11), the gas mixing section (14) and the afterburner (19) are all connected to the pressure sensor base (16) and the temperature sensor base (18), the pressure sensor and the temperature sensor are fixed, and the pressure and temperature data of the trajectory in the engine body are obtained.

2. A modular sub-assembly and assembly solid rocket engine test bench device according to claim 1, characterized in that: A porous medium plate (22) and a probe (23) are arranged inside the gas mixing section (14); the porous medium plate (22) is embedded in a groove in the gas mixing section (14); a cover plate is added on the top and connected by bolts; a square hole is arranged in the middle of the cover plate; and the top end of the probe (23) is connected to a sensor of the gas mixing section (14).

3. A modular sub-assembly and assembly solid rocket engine test bench device according to claim 1, characterized in that: The flow regulating section (10) adopts a gradually contracting-suddenly expanding form, accelerating the upstream subsonic high-pressure gas through the flow regulating section (10), thereby reducing the pressure and temperature.

4. A modular sub-assembly and assembly solid rocket engine test bench device according to claim 1, characterized in that: The circular-to-square transition section (8) and the flow stabilizing section (9) both adopt a head-to-tail flange structure, and the flange plate (21) is connected to the circular-to-square transition section (8) and the flow stabilizing section (9) by welding.

5. A cold flow test method for a modular sub-assembly and assembly solid rocket engine test bench device according to any one of claims 1 to 4, characterized in that: The specific steps are as follows: Step 1: Connect the axial air inlet pipe and the lateral air inlet pipe to the axial air inlet hole (6) and the lateral air inlet hole (17) respectively by means of threaded connection; Step 2: Build the Schlieren system in a "Z"-shaped optical path; Step 3: Start the test by first turning on the high-speed camera, pressure sensor and temperature sensor to record the flow field inside the engine without gas; Step 4: Open the valve of the air supply system and inject high-pressure nitrogen and argon into the engine. The gas flows into the particle mixing section (7) and the steady flow section (9) through the axial air inlet hole (6), enters the engine, and is accelerated into the front combustion chamber (11) through the flow regulating section (10). The gas flows into the top and bottom of the fuel gas mixing section (14) through the lateral air inlet hole (17), flows steadily into the flow field inside the engine through the porous medium plate (22), meets and mixes with the axial incoming flow, and flows out of the engine through the afterburner (19) and the tail nozzle (20); Step 5: After waiting for the pressure inside the engine to stabilize, close the air supply system valve, check the images recorded by the high-speed camera and the data collected by the sensor, and analyze the results.

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